No - each smoothing level divides each edge by two, giving you four polys for each one - the only way to keep the shape sharp is to re-enforce the edges with either cutting in new edges next to existing edges, beveling, etc. There is another method to stop smoothing by excluding edges from the smoothing process. None of these are really practical in modelling.
128 Meg on-board graphics is pretty weak for CG. Until you get a new machine, you could use Anim8or - It really is a great little app for learning, free, very low on resources and has a few very advanced features for such a light app.
